Field of the Invention
The present invention relates to an image forming apparatus which includes an opening/closing unit provided to be freely opened or closed.
Description of the Related Art
In recent years, there are various proposals for enhancing operability of portions that a user operates for the purpose of improving a quality of an image forming apparatus. Among them, in a so-called door portion which is provided as a part of the outer case of the image forming apparatus, in order to handle trouble-shooting in the event of a problem, such as a jam occurrence, an impact buffering portion is provided to buffer an impact generated at a time when the door is opened up to a predetermined opening position and stopped by a stopper member. There is a proposal to prevent damage to a main body of the image forming apparatus or to the door, caused by the impact generated when the door is opened, while maintaining good operability for the user.
Specifically, the following proposal is made for the impact buffering portion for such an opening/closing operation of the door.
First, an opening/closing mechanism of a cover of the image forming apparatus disclosed in Japanese Patent Laid-Open No. 2006-83551 is provided with an arc groove having a gear portion disposed therein, in a vicinity of a rotation center of the opening/closing mechanism, and includes a gear which is meshed with the gear portion inside the groove and which can be freely rotated. In the gear, a rotary damper is included in a rotating axial direction, and a control force (load) is applied during an operation of opening or closing the cover. In this way, an impact generated when the opening/closing operation of the cover ends is buffered by applying the control force.
Next, in Japanese Patent Laid-Open No. 2007-279274, a load is applied to the opening/closing door by a rack and an oil damper which control the rotation of a pinion. In addition, the pinion and the rack are configured to be separated in an operation where the damper effect is not required.
On the other hand, there is an image forming apparatus in which a plurality of opening angles is set in one door. The plurality of opening angles are generally set as an opening angle for trouble-shooting performed by the user, and as an opening angle for regular replacement of components, or replacement of units, which is performed by a maintenance manager, such as a so-called service man.
In other words, as a main trouble handling performed by the user, a process of removing a jammed sheet caused by a jam occurrence, or other sheets remaining in the image forming apparatus, is exemplified. In this case, the door may be opened only by an amount sufficient for removing the jammed sheet. However, in a case where the maintenance manager replaces components or units, in the course of regular maintenance, using the opening portion of the same door, a switching portion is configured to perform a switching operation to open the door to a greater degree than a case in which the jam recovery is performed, in order to ensure the door opens smoothly without causing damage in the process of replacing components or units.
In Japanese Patent Laid-Open No. 2003-241466, there is provided a regulation portion which regulates the door, to be opened at a plurality of opening angles, according to a usage, such as an opening position for the jam recovery performed by the user, and an opening position for the maintenance performed by the manager, such as a service man. Furthermore, in a case where the door is opened up to the opening position for the jam recovery, among a plurality of opening positions, a load is applied to the movement of the door before the door reaches the opening position, and an impact generated when the door is stopped is buffered. However, it is desired to minimize the apparatus for applying the load to the movement of the door.